Process of making rubber articles having cores and apparatus therefor



F. T. ROB

PROCESS OF MAKING RUBBER ARTICLE H RE D APPARATUS THEREFOR.

APPLICATION ED ,19

1,387,805. Patented g- 16, 1.

2 SHEETS-SHE F/a Z a A 12 20 y /a a 3 /6 3 I f/m lar /9 A5, p

F. T. ROBERTS. PROCESS OF MAKING RUBBER ARTICLES HAVING CORES AND APPARATUS THEREFOR.

APPLICATION FILED [1130.29, 1919.

Patented Aug. 16, 1921.

2 SHEETSSHEET 2- 73m; wax,

UNITED STATES PATENT OFFICE;

FRED rnomes ROBERTS, or cmvnnann nnmn'rs, 01110, assxenonwo rumour:

RUBBER CONSOLIDATED, INTO OF .PHILADELPHIA, PENNSULVANIA, A CORPORA- TION' OI DELAWARE.

' Application filed December To all whom it may concern:

Be it known that I, FRED-THOMAS Ron- EBTS, a citizen of the United States, residing at Cleveland Heights, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Im rovement in rticles Havexact description, re erence being had to the accompanying drawings. This invention relates to a method and apparatus for efliciently and rapidly manufacturing closed rubber articles containing cores. An instance of a use of the invention is the manufacture of centers for baseballs, comprising a cork sphere surrounded by a rubber shell.

In addition to rapidity and chea ness'of manufacture, which are objects of tie present invention, it has also the important fea- Processes of Making Rubber ing Cores and Apparatus Therefor,

- ture of substantially exhausting the air between the core and shell, thus insuring a snug and continuous junction, and preventing the formation of blisters between them.

11 carrying out my invention, I provide means for pneumatically seating the rubber shell in mold cavities, and then, after a core isplaced within the rubber-lined-cavities and such cavities brought together, I exhaust the air between the core and shell. The invention includes the above men-.

tioned steps as a process and also an apparatus which may be employed in performance of'such process, all of which is hereinafter more fully explained.

In the drawings, Figure lis a vertical cross section of a suction mold for use in performing the process, adapted particularly for the manufacture of base-ball centers; Fig. 2 is a plan of such mold; Fig. 3 is an enlarged vertical section throu h one of the cavities of the mold, showing t e rubber stock seated in the cavity and the core lying loosely therein; Fig. 4 is a vertical section through two cooperating molds after the rubber shell has been completely seated and as the mold members are just coming together; Fig. 5 is a cross section through the two mold members after they have been brought finally together under pressure; Fig. 6 isa much enlarged cross section of PROCESS OF MAKING RUBBER ARTICLES HAVING 'CORE A ND APPARATUS THEREFOR.

29, 1919. Serial No. 348,095.

the hollow puncturing needle employed; Fig. 7 is a cross section of a suitable vulcanizing mold which may be used in carrying out the final ste of the process.

As shown in -igs. 1 to 6 inclusive, .10 indicates a plate or block forming the body of a multiple mold, this block having a series of cavities. 11 for the variousjarticles, each cavity being sfirrounded by an annular cutting rib 12 and the whole series of cavities be'ng surrounded by grooves 13 4 in the face of the block. Each cavity 11 and the groove 13 are in'comm unication with a suction chamber-15 in the base of the mold from which leads a suitable exhaust pipe 17. The connection between the grooves 13 and the suction chamber is simply by occasional holes 18. The connection between each cavity and the suction chamber involves a hole 19 through the body of the block and a peculiar hollow needle 20 occupying thecavity-end of this hole and proectmg into the cavity, as hereinafter explained.

The hollow needle 20 is so arranged in the base of each mold cavity that it provides for two suction connections to the cavity, one at the extreme base of the cavity and the other at or near the point of the needle, which projects'into the cavity. As shown on an enlarged scale in Fig. 6, the needle may have a threaded shank 21 screwed into a threaded enlargement 22 of the hole 19, and may have a collar 23 snugly occupying a recess in the base of the cavity above the collar] vThe needle is shown as extending in a conical form, (indicated by dotted lines 24) flattened on opposite sides 25, such flattening providing for the convenient application of a wrench for screwing the needle into or out of place. A bore 26 extends axially through theneedle from end to end, and a lateral opening 27 extends into this bore from the exposed face -,of the collar immediately adjacent to one of the flattened sides of the needle. It will be seen from this construction that air may be exhausted from a cavit at the point of the needle andalso immediately adjacent to the surface of the cavity, the purpose of which will be hereinafter apparent.

In the operation of my process, a sheet of fBy means ofthe suction through the point rubberis laid across the face of the mold into the annular- I i lied to the cham r 19, this suction acting in the groove13 to draw the rubber into the making a tight connection between:

down somewhat ihefiiber, and ?then pressed 4 oove 13, and suction ap oove,

' t e'rubber and'the mold entirely around the except at the needlewhere the -r across the point of theneedle. The suction H through'the point of the needle is not suf- -ficient to cause the rubber) to be punctured the vacuum groove.

contact withthe Wall of the cavitgggs at A, r P s s by the needle so that the, rubberlining of the'c'avity extends upwardly at the, base por- 'wise snugly'fits the wall of the cavity, as

.tion across the point of the needle but other"- 7 illustrated by the rubber portiona" in Fig. 3.

Fig. 3; then the other rubber-lined mold After two sheets of rubber have been seated in two mold 'membersby suction, as

f articles, and No. 221,961, filed March. 12,

described, the ball center is placedin oneo the mold membershaving u wardly facing cavities, as. illustrated: by t e' center in member is placed in invertedposition over the cores, as shown n being maintained throughout this operation. Then the two 'mold members are brought gradually together under hydraulic pressure while the suction is still maintainedr As the portions of the rubber over g the annular ribs 12rare coming into en gagement.-the core resses on the inward projection of the ru, her a. and causes the needle to puncture it. Fig. 4 shows the position as this puncturing is just taking lace. As soon as the mold members are suction connection from the suction chamber 15 through the point of the needle to the space between the rubber core and shell. At the same time the two hemispheres of rubber are joined together ina seam and the sur lus stock is sheared oil by the annular IlbS 12.

e needle, the air surrounding the core -within the shell isimmediately exhausted.

The completion of the closing movement under hydraulic pressure brings the parts into the osition shown in Flg'. 5, where the shell is pressed snugly and evenly into contact with the core'and the meeting edges of the shell are joined in a seam and the rubber surrounding such seam is cut ofi by the ribs 12. v

Afterthe operation described; the mold members 10 are separated. In such separation one of the needles i becomes withdrawn from each finished article, and the Fig. 4, the suction 'hausting t rought firmly together the puncturing has been completed so thatthere is then a article i then removed ;(manuall y or other.

planeof the two mold plates, and thus the small external fin, or roughness, at the seam, is lost in the vulcanization, and a smooth uniform hollow spherical 'sh e ll is, 3 f

produced, containing the spherical core.

I ,It should be notedthat the suctional' clamping of the rubbersheet' to the mold v illustrated herein,.is claimed in my applis cations No. 154,072, filed March 12, 1917, fora method of making hollow rubber 1918, for molds for hollow rubber articles.

, readily f 'wi-thdrawn from the needle thereo When rounding rubber closes. the openingwhich suitable. mold 1 :f i

The method of pneumatically seating rubber stock and thereafter exhausting the air between it and a second member. con- "95. No. 230,625, filed April 25, 1918, for a tacting with it .is claimed in my application process of and apparatus, for making hollow rubber articles.

I claim: i

1. The method of making'rubber articles having cores, comprisin seating rubber stock for the shell of the article in two mold cavities, bringing such rubber-lined cavities into conjunction with an interposed core occupying'one of the cavities and exe air between the rubber shell and core. I

2. The method of making rubber articles Y having cores, comprising pneumatically seating rubber stock for the shell of the article intwo mold cavities, bringing the shells in the cavities into en agement and causing the body of the shel to embrace a core, and during such operation exhausting the air betweenthe rubber shell and core.

3. The method of, making rubber articles having cores, comprising seating rubber stock for the shell of the article, placing within such seated stock the core, bringing therubber-lined cavities into conjunction about the core to join the edges of the shell to each other and shear oil the surplus stock around such junction, and during such joining operation exhaust ng the air from the s acebetween the shell-and core.

4, 6 method of making-rubber articles having cores, compris' rubber stock for the s ell of the article,

lacing within such seated stock the core,

ringing therubber into engagement at the seating by suction rims of the cavities to join the edges" of the shell to each other and shear off the surplus stock around such junction, and after the edges are abutted exh the space between the shell and core,

5. he step in the method of making 'cored rubber articles comprising exhausting the air between the core and an inclosing shell duringthe formation of the article.

6. The step in the method of making cored rubber articles comprising exhausting the air between the core and shell after the shell has completely inclosed the core and while I it is being pressed into snug surface engagement therewith.

7. The method of making cored rubber articles comprising forming a shell in cup shaped portions and bringing such portions into edge engagement about an internal core, and during the operation exhausting the air between the core andshell.

8. The method of making cored rubber articles comprising forming the shell in a series of depressions in a rubber sheet, bringing two of such sheets into engagement around the edges of the depressions and about an internal core, and during the operation shearing off the surplus stock around the abutting edges and exhausting the air between the core and shell.

9. The method of making rubber articles comprising seating rubber in mold cavities, such cavities being provided with hollow needles extending into them, which needles have openings closed by the rubber when it is thus seated, and thereafter forcing a core into engagement with the rubber and thus causing the needle to puncture the rubber, suction acting on the space between the core and rubber after such puncturing.

10. The method of making cored rubber articles consisting of seating rubber sheets in mold cavities by suction, such cavities being provided with hollow needles extending into them, which needles have openings closed by the rubber when it is thus seated, and thereafter forcing the core into engagement with the rubber and thus causing the needle to puncture the rubber, the suction being continued after such puncturing, and acting through the needle on the space between the rubber and core. 1

11. The method of making rubber articles having cores, comprising pneumaticall seating rubber stock for the shell of the article in two mold cavities, bringing the shells in the cavities into engagement and causing the body of the shell to embrace a core, and thereafter transferring the article to another mold ard vulcanizing it.

12 The method of making cored rubber articles comprising forming 'a series of depressions in a rubber sheet, bringing two of such sheets into engagement around the edges of the depressions and about an interausting the air from and vulcanizing it.

nal core, and during the operation shearing ofl" the surplus stock around the abutting edges and exhaustin air between the core and shell, then trans errin the core-covered article to another mold amlvulcanizing it.

13. The method of making rubber articles comprising seating rubber in mold cavities, such cavities being provided with hollow needles extending into them, which needles have openings closed by the rubber when it is thus seated, thereafter forcing a core into engaglement with the rubber and thus causing t e needle to uncture the rubber, ex hausting air from t e space between the core and rubber after such uncturing, and then transferring the artic e to another mold 14. An apparatus for making rubber a'rticles consisting of a mold member having a cavity, a hollow needle extending into said cavity, means for establishing suction through the needle adjacent to its point, and means for establishing suction from the cavity independently of the point of the needle.

15. The combination of a pair of coacting mold members, rounded by a cutting rib, a .hollow needle carried by each mem er and extending into its cavity, means for establishing suction through the needles adjacent to their points, and means for establishing suction from the cavities independently of the points of the needle.

16. The combination of a mold member having a cavity, a 'hollow needle extending into the cavity, a suction passagewav'comeach having a cavity sur;

municating with the cavity through the hollow needle, and a suction passageway communicating with the mold cavity adjacent to the surface of the cavity.

l7. The combination of a mold member having'a cavity, a hollow needle extending into the cavity, a suction passageway communicating with the cavity through l'the point of the hollow needle, and an additional suction passageway communicating with the mold cavity adjacent to the base of the needle.

18. The combination of a mold member having a cavity, a suction chamber in the mold member, a passageway from said chamber to the cavity, a hollow needle occupying, such passageway and extending into the cavity, there being additional communicaopenix ilghadjacent to the'.base of the cavity.

20. ejcombination of a mold member having agcavity, and pa eway to the cava' hollow needle occupying said passageway and extending into the cavity having a bore through it, and. a lateral 'eninginto such .bore adjacent to the sur ace of the cavity. a a,

21. The combination of a mold member having a cavity, a suction chamber, a passageway from the suction chamber to the cavity, a hollow needle occupying said passageway and extending into the cavity having a bore throu h it longitudinally, and a lateral passage rom such bore to the exterior of the needle adjacent to the surface of the cavity.

22. The combination of a mold having a cavity, a passageway leading thereto, a hollow needlescrewing into such passageway and extending into the mold cavity andhaving an opening adjacent to its. point, and means for exhausting the air from the cavity independently of. the opening at the point of the needle.

23. The combination of a mold member having'a cavity, a passageway to the cavity, a hollow needle having a screw-threaded shank threaded into the portion of the passageway adjacent to the cavity, said needle extending into the cavity and having an opening adjacent to its point and a lateral opening intheside; wall of the needle adjacent to its base communicating the bore thereof.

24. The combination o f'a mold having a beyond the collar into the bore of the needle.

25. The combination of a mold having a cavity, a suction passageway leadi therefrom, a hollow" needle having a t readed shank screwing into said passageway, the slde of said needle being flattened, and a lateral opening at the base of such flattened portion into the bore of the needle.

2d. The. combination of a mold member having a series of cavities therein, each surrounded by an annular cutting rib, a suction chamber, a semes of passa ways fromthe various cavities to the suctlon chamber, and

hollowneedles occupying the various passageways and extending into the cavities, sa1d needles having openings adjacent to their points, and there being additional suction passageways to the suction chamber from the cavities adjacent to the walls thereof and independently of the points of the needles. I

In testimony whereof, I hereunto aflix my signature. I

FRED THOMAS ROBERTS. 

